The problem is trying to figure out if the blood found its way into the urine because of something connected with the diet or whether something else happened independant of the diet but at the same time.

I did a quick web search and could only find one instance matching the search phrase "low carb blood in urine". And even that wasn't exactly about a low carb diet. With the thousands of people using low carb it seems unlikely that the diet would cause this problem with no one posting about it.

But, as you have an ongoing medical condition it might be complicating the usual course of the diet. The doctor who is treating you for the bowel problem should also know about any change in your diet. If it were me, I would do this diet but be carefully monitored by my doctor.

Slowday